1. Field of the Invention
The present invention relates to a delustering coating composition excellent in the abrasion resistance.
2. Description of the Prior Art
Molded articles of thermoplastic resins such as polymethyl methacrylate resins, polycarbonate resins, ABS resins, nylon resins and PET resins are ordinarily lustrous, and this property is important in some uses. However, there are many application fields in which delustered molded articles are preferred. Recently, matting plates and non-glaring plates in which reflected light is scattered to obtain a delustering effect without degradation of optical characteristics such as the total luminous transmittance have been used in various fields.
As the conventional means for delustering molded articles, there are adopted a method in which a molded article is coated with a paint in which fine particles of silica, titanium oxide or aluminum oxide are incorporated, a method in which these fine particles are incorporated into a resin and they are precipitated on the surface by some means at the molding step to deluster the surface, a method in which molding is carried out in a mold having fine convexities and concavities on the surface thereof, and a method in which cast polymerization is carried out in a cell having fine convexities and concavities on the surface thereof. A paint having silica, titanium oxide or aluminum oxide incorporated therein is defective in that when the paint is stored, the dispersion stability is degraded with the lapse of time and solid precipitates rendering re-dispersion difficult are formed, and the degree of the delustering effect is changed. In the method using a mold or cell for transfer of the surface pattern having fine convexities and concavities to the surface of a molded article, close attention should be paid to maintenance and control of the mold or cell, and this method is not completely advantageous. Furthermore, according to these conventional methods, delustered molded articles can tentatively be obtained, but since the abrasion resistance or the scratch resistance of the surfaces of the molded articles are inferior, the molded articles are readily damaged and the delustered surfaces are often impaired.